Fluid-pressure-actuated tool



Aug. 21, 1923.

E. H. SHAFF FLUID PRESSURE ACTUATED TOOL 2 Sheets-Sheet 2 l Filed Aug,2, 1920 Patented iig. 2l, `1925?.

ERNEST n; SHAFT, or GRAND HAVEN, MICHIGAN, lissieivon To winnieia H.KELLER; INC., or GRAND HAVEN, iiiioniefnN, n ooRronnTroN or iaroriieniv.1

vrLUID-PRESSUaE-ACTUATED Toon*v Application led August 2, 192C. VSerialNo. 400,'650.V A

Z 1o rzZZioio/ni 'it 71mg/ concern: 1

Be it known that I, ERNEST H. SHAFF, a ycitizen of the United States,residing at Grand Haven, in the county of Uttawa and State ofhlichigamdiave invented certain new and 1 useful Improvements in `Fluid-Y Pressure-Actuated Tools, of which the following is a specification. yY

My invention relates to fluid pressure a-'etuatcd tools and morelspecifically to improvements in the construction of the cylin-- valvemember which may be quickly shifted and may even befmade of sheetmetalif desired. f Y f Y.

Another Vobject is to provide means for ciitting olf the flow through aset of tubular passageways by movement of a= barrierthrough less thanthe diameter -of apassage, at the same time providing an unrel-l` ofFig. 5. Fig "2 is a similar sectiony of the inner portion of the tool onlines 2-2 of Fig. 5. 3 isa perspective view of the valve member. Figs.'4l, V5, G and 7 are transverse .sections on the lines %4, 5 5,

-iand 7-.7 ofFig. l lrespectively show-V ing the arrangement of thesages' V- Y In the embodiment of my` .invention 'rselected forillustration, the tool comprises a cup-shaped .head member lO preferablyformed integral with Vthe handle portion 12 ports and paswhich carriesthe manual control trigger .14;V

for controlling" the dcliveiypofjlive pressure fluid to the passage 16andthe annular chamber 18 surrounding,the valve casing.

VThe headrlO is threaded onto the main cylindrical body member .2O `andlocked in position by suitable lockingineans 2l which Y also forms ashield overthe exhaust ports as will hereinafter appear. The front endof the body may receive a' rivet seti 24 or any other lsuitable tool. Y.Y y

A valve chamber comprising two incnijA bers V2,6 and 28 cooperatingtoformv the chamber and receivingthe valveL 30 between them is supportedbyY tight fitting engagement Vof the member 26 in the-body 2O and' byabutment of the member 28 with the end face of `theincmber 26. Thepistonk 32fre-fl ciprocates inatube 3a extending throughoutthe length ofits stroke and having an outwardly directed `lip 36 its frearendentering anan'nular rabbet in the valve cas-v ing member Y28 and'clampedwith'the valve casing members by screwing the headlinto v.

position. .At its vforward endgithasjtight fitting engagementwith ashortsection of `thebody except for a. pluralityv of extending .grooves'BSwhich may kbe vclit` axially either in the outer periphery of the tube'or the inner periphery of thecylinder videV passages for a purposewhichhereinafter explained.:

rThe valve 30 comprises-"a front of small diameter sliding, on theoutside of portion the tube 34 and having a "slightly enlarged lip 40 atitsfrent ',end, an outwardly directed portion 42, and a rearwardlyextend ing. cylindrical portion ell.. The rear kedge of therear portion4A operates as asma-.ll

pressurereceivingarea inshifting thel Vvalve Y forward and the frontside of the outwardly directed portion 42. operates asa large prese surereceiving 'area'Y in shifting the if'al've rearward.

VReferring firstlto `2; with the vi'ilxf'ein l Vthe position shownliveinotivejtiuidenters through alined radial ports 45, Grand 4:8

.formedy in the valvefcasing members and Y tube and forcesthepistonnforward'. Ll have 11oAY in the body with the space covered bythe shield 2l and thus to the atmosphere. Near the end ot the'iorwardstroke Vthe rear end ot the piston will 'uncover a set'ol2 radial ports60 through which live motive fluid will escape to fill the chamber 50.KYrihe initial-rush et live motive fluid 'from the chamber throughpassages 52 will build up enough pressure against the liront 'face ot'the outwardly directed portion to shit't the valve luirtway back to theposition shown in i carrying the enlarged lipl 40 past the groove andthus disconnectiniY the valve chamber from theef-:haust passages. Vrthepressure thereupon rises immediately in the chamber in trent of theoutwardly directec portion 42 to full'line pressure, forcing` the valveback into the position shown lin Fig. l. it should be clearly understoodthat these two steps vare setxforth primarily because they maytheoretically eXist but that the shitting of the valve is practicallyinstantaneous and occurs upon the delivery ot live motive fluid throughchamber into passages Y nections between the various passages.

This shifting of the va.ve is practically coincident with the impact oi'the piston 32 anjainst the tool 24, and rear-ranges the con- Reierrinpyto. Fig. l, showing the rear position ot' the valve, it should be notedthat the rear portion ot the cylinder is in direct communication throughradial'ports G2 with the eX- haust passages 5G and 58 so that thepressure back ot the. piston drops immediately and remains practically`atmospheric during.; the. return stroke. VThe high pressure air storedin the chamber at' the instant the valve shifts is prevented fromreentering' the cylinder bach ot the piston through portsv by suitablemeans such as resilient leat valves 64overlyin'g the, port-s, andexpands tl'irough passages 38 into the space in trout et the piston,operatingr to pick up the pirton on its recoil tromlt-he toolVandreturnV it to the rear end 'of the cylinder.r As the volume ot Ythecylinder is considerably larger than that of the chamber the pressuredriving the'V piston back falls quite rapidly so that the-velocityattainedV at the end et the return stroleis less than that with whichthe piston struclrthe tool.,1 after traveling the entire stroke withfull line pressure behind it'. n f

luringV the shittingl of the valve the air trapped back of' theoutwardly directed portion 42 may escape through a. port 66 in the valveitseltl into a long annular groove 68 'in the outerV valveV casingmember and through passage 70 into the exhaust passages 56. Movement ofthe valve to the rear position also uncovers a smal auxiliary passage 72which continuously delivers a limited amount ot live motive fluid infront of the outwardly directed portion 42. 'This vaintains the pressureat this point a trifle above that-in the chamber 50 during the expansionon the return stroke and thereby prevents premature shifting ofthevalve.y lt will be apparent on reference to F 2 that the forwardposition of the valve does not carry 'its rear portion 44V completelyout ot the radial ports through' which live motive tluid is being'supplied to the cylinder but that approximately only halt ot: the area.ot'these ports is uncove-red Vby the valve. To prevent cuttingl down thearea provided at this point, I torni annular grooves 74 and 76 inthemembers 26 and 26 respectively. As these vgrooves form a chamberextending* both outside and inside ot the rear edn-e ofthe valve andcommunieating` with all ot the radial passages, lthe area at this pointmayreadily be made a tritle greater than.; at other points, and at vthesame time complete closure Yor" the inlet passa 'es may be accomplishedby moving the v 7e through only halt of the diameter of the radialpassages. When shifted tothe rear, the valve crosses they annularchamber and enters a. smaller chamber Y7S which is K completi-ilylfilled by the valve member. rlhis smaller chamber in comnuinicationwith the V`cyliiuler through a passage 8O and with the annular supplychamber i8 through a passage As lonsY as the first mentioned passage 80during' the return 4stroke remains in communication with atmosphericpressure in "the rear portion ot the cylinder the valve 'will remain inits rearmost position. As the pif-'tonrovers the portsi62 ou the rearstroke, the pressure in the rear portion ofthe cylinder and in thepassageway 80 will begin to rise and' an instant later.'- the pistouwill cover the passage 8O itself, whereupon the pressure in chamber 78will innnr-idiately rise to full line pressure and the valve will bethrown forward again. This action may readili7 bel timed to occurybetere they pistonY covers the radial passages 48 so that thek j pistonis cushioned on live motive fluid having' the fulll linepressure andimmediately thrown Vback against the tool. It should, however, he'notedthat in'I case the valve werevto stick or not operate quickly enough toreceive the piston as abovestated, that the air trapped lwhen the pistonVpasses portsY 62 cannot escape, and it will in any event cushion thepiston so that itcannot strike `the face of the head 10.y Y y' lt willbe seen that the tube 34 is supportedv at one end by engagement withthe'body v20.

las

and at the other end by engagement with the valve casing' and head sothat no extra annular' member is necessary for mounting theV tube. rlhepiston is also subjected to less wear as it makes its entire stroke incontact with a single cylindrical continuous surface which may bemachined to a `much more satisfactory fitting engagement with the pistonthan a plurality of different meinbers. The wear on the valve member isalso diminished as it travels only a small distance and is in contactwith surfaces which merely guide it in its own movement. i

lllhile l have illustrated and described in detail I.he preferredembodiment of my invention. it should he clearly understood that thedisclosure is merely for purposes of illustration and that manymodificationsand variations will naturally occurto those skilled in theart. l aim in the subJoined claims to cover all such legitimate varia-Ytions and modifications.

l claim as my invention l. In a fluid-pressure--actuated tool, a piston,a tubular member suliporting` ,andguiding said piston, inlet and exhaustportsV adjacent one end of said member, a` body supportingsaid memberand spaced therefrom to define a storage chamber, and an automatic valveopening said inlet ports and connecting said chamber to exhaust passageson the forward stroke, and closing' said inlet ports, opening` saidexhaust ports and disconnecting;- said chamber from the exhaust passagesVon the return stroke.

2.111 a fluid pressure actuated tool, a main cylinder member, a valvecasing' comprising two annular members encircling said main cylindermember, said cylinder member and casing;` cooperating to define twoannular spaces of small radial dimensions an d different diameters andan annular space of relatively large Yradial dimension havingl a smallerdiameter not lgreater than the small diameter of one of said firstmentioned spaces and an outer diameter not less than the outer diameterof the other space.

body member having an annular rabbet formed in one end, a valve casingmember o. In a fluid-pressure-actuated tool, aV

having one endl entering said rabbet and an annular rabbet at its otherend,l

having a second valve casing member engaging the annular rabbet in saidfirst valve casing' tioned casing member and at its opposite i Vendhaving a close fitting sliding engagement with said'body member, and ahead mounted on said body i'eember and operatinni by engagement with theflange end of said main cylinder member to clamp all the parts securelyin position.

4.-: In a 'Huid-pressure-actuated tool, a tubu-. larbooy member, asleeve within said body' member spaced therefrom to `define an annularchamber. a piston sliding in said sleeve its and guidedtherebythroughout Ventire stroke, ports in said sleeve'in a position to `beuncovered by the piston near the end of theV forward stroke, andvpassagreways establishing coniinunication between said annular chamberand the cylinder at its front end` said annular chamber serving as anexhaust passage during the forward stroke until saidY portsare'uncovered and subsequentlyeperating to store live motive duid. anddeliver it through said passageways to yreturn the piston. f

5. In a fluid-pressure-actuated tool, a tubularbedy member, a sleeveWithin said `body niemberspaced therefrom to define an annular chamber,a piston sliding` in said sleeve and. uided thereby throughout,itsV.entire stroke` ports in said Vsleeve in a position to be uncovered bythe piston near the end of the forward stroke, and a valve adjacent therear end of the cylinder forautov matically delivering live motive Huidto. Vthe rear end of the cylinder and connecting said annular chambertoexhaust passages on thejforward stroke `and for connecting the rearendof the cylinder to the exhaust passages and disconnecting said annular'chamber therefrom on the return stroke.

soV

set my hand.

ERNEsT Hfsiiarr.

